Select the correct answer.
a body travels 10 meters during the first 5 seconds of its travel, and it travels a total of 30 meters over the first 10 seconds of its travel. what is
its average speed during the time from t = 5 seconds to t = 10 seconds?
a 2 meters/second
b. 3 meters/second
c4 meters/second
d. 5 meters/second
e. 6 meters/second

C. Average Speed = 4 m/s

Explanation:

Average speed is defined as total  distance travelled per unit time taken

From = 5s to = 10 s

Total time = 10 -5 = 5s

Distance travelled in first 5s=  = 10 m

Distance travelled in first 10s = 30 m

Total distance between 5 s- 10 s = 30 - 10 = 20 m

!! Please look at the attached image

a mercury barometer is a device that uses the physical properties of mercury in a tube to measure barometric pressure. mercury barometers are used for : -

1. measurement of atmospheric pressure  

2. determining the altitude of a place

3. weather forecasting

4. calibration and checking of aneroid barometers

5. application in fluid mechanics

6. measurement of pressure in aircrafts

7. surface weather analysis

8. preparation of barographs

9. usage in physical sciences like physics, astronomy & chemistry

10. preparation of aircraft altimeters

characteristics of mercury barometer : -

1.used to define and measure atmospheric pressure.

2.on the average at sea level the column of mercury rises to a height of about 760 mm.

3.this quantity is equal to 1 atmosphere.

4.it is also known as standard atmospheric pressure.

5.a barometer in which the weight of a column of mercury in a glass tube with a sealed top is balanced against that of the atmosphere pressing on an exposed cistern of mercury at the base of the mercury column, the height of the column varying with atmospheric pressure.